[Stage diagnostics for postinfection revision of hip and knee replacement: value of laboratory parameters and...

In the case of two-stage infect revision arthroplasties of hip and knee joint, of primary resection arthroplasties and before implantation of arthroplasties after septic arthritis the accuracy of preoperative laboratory parameters and antigranulocyte scintigraphy was analysed. Furthermore, we stained the intraoperatively taken joint synovial samples with hematoxylin-eosin and also with antibodies against human neutrophil elastase in order to investigate if immunohistological examination provides further or different information.

In 24 patients with intraoperative verification of infection we calculated sensitivity, specificity, positive and negative predictive values for laboratory tests, antigranulocyte scintigraphy and the most suitable combination of both. The joint synovial samples stained with antibodies against human neutrophil elastase were compared to those stained with hematoxylin-eosin according to the criteria of Mirra.

We observed the best results for the combination of C-reactive protein and antigranulocyte scintigraphy with a sensitivity of 1, a specificity of 0.92, a positive predictive value of 0.75 and a negative predictive value of 1. No additional or different information was observed by the immunohistological stained samples.

Stage diagnostic using C-reactive protein and antigranulocyte scintigraphy provides accurate information to assess the status of infection before hip and knee replacement after infect revision. Additional immunohistological staining besides the routinely taken hematoxylin-eosin staining of joint synovial samples is not recommended.